systematics study of pattern and processes associated with biological diversity and diversification...
TRANSCRIPT
![Page 1: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/1.jpg)
Systematics
• Study of pattern and processes associated with biological diversity and diversification
• Taxonomy – study of classification (hierarchy, naming Diversity)
• Phylogenetics – study of evolutionary relationships between species and groups (Diversification)
![Page 2: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/2.jpg)
![Page 3: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/3.jpg)
![Page 4: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/4.jpg)
Species Concept
• Biological species concept – definition
• All species concepts have limitations
• Classification is a human construct
• Importance of defining a species
![Page 5: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/5.jpg)
Phylogenetics
• Homologies
![Page 6: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/6.jpg)
Phylogenetics
• Convergence
![Page 7: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/7.jpg)
Phylogenetics
• Apomorphy – derived trait
• Pleisomorphy – primitive trait
![Page 8: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/8.jpg)
Subspecies
Populations – coat color of subspecies match local substrate
![Page 9: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/9.jpg)
Evolution
• Macroevolution – lineages of species and major groups, changes in diversity
• Microevolution – changes in species, short and longer term; contemporary species
• Not segregated; difference in scale
![Page 10: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/10.jpg)
Macroevolution
• Evolution does not proceed at a uniform rate
• Bradytelic – lineages changing at slower rates than typical
• Tachytelitic – faster rates than typical
• Horotelic - typical
![Page 11: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/11.jpg)
Punctuated Equilibrium
• Proposed abrupt changes in lineages following long periods of stasis
• Mass extinctions adaptive radiation
• Does not contradict natural selection; still a key process in punctuated equilibrium
• Gradualism also occurs
![Page 12: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/12.jpg)
![Page 13: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/13.jpg)
Gradualism
![Page 14: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/14.jpg)
Macroevolution
• Rapid Radiation not always with mass extinctions
• Cambrian Explosion
• Mass extinctions may not be random
• Species selection (large sp. end Cretacrous
![Page 15: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/15.jpg)
Mechanisms of Evolution
• Mutation
• Genetic drift
• Gene flow
• Natural selection
![Page 16: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/16.jpg)
Adaptation and Range Expansion
• Range of a species includes range of populations
• Populations on edge of range may adapt to a limiting condition
• Some species may not have capacity to adapt morphologically, physiologically, or behaviorally peripheral conditions
![Page 17: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/17.jpg)
Adaptation and Gene Flow
• Gene flow changes allele frequencies of populations
• Can, however, homogenize gene pool through exchanges between populations
• Restricts further adaptation to local conditions
• Other limitations to adaptation limit range expansion (not all species have wide ranges)
![Page 18: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/18.jpg)
• Distribution of karyotypes of Palestine mole rat (Nannospalax ehrenbergei)
• Lack of overlap reduced gene flow
![Page 19: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/19.jpg)
Geographic Variation
• Geographic isolation facilitates genetic drift and natural selection
• Impedes gene flow
• Genetic drift – isolation of small populations
• Founder effect
![Page 20: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/20.jpg)
• Divergence of monarch flycatcher• Founder effect – colonizers of islands
created gene pool for each
![Page 21: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/21.jpg)
Allopatric Speciation
• Speciation resulting from geographic isolation
• Broader definition applying environmental and physical barriers
• Dispersal barriers in heterogeneous environment
• Geographic isolation after dispersing to another habitat (e.g., island to island)
![Page 22: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/22.jpg)
Allopatric Speciation: Vicariance
All in Family Ranidae
Endemic Mad.
![Page 23: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/23.jpg)
Sympatric Speciation and Adaptive Radiation
![Page 24: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/24.jpg)
Extinction
• Changing of the guard (dominance in given niches)
• Cephalopod molluscs teleost fishes
• Dinosaurs & reptiles birds and mammals
• Species are eliminated or supplanted in their lineages
![Page 25: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/25.jpg)
Extinction
• Probability of extinction independent of evolutionary age
• Is related to taxonomic and ecological status
• Small, herbivorous mammals lower extinction rates than large carnivores
• Same true for marine invertebrates
• Ties back to point about more niches for small organisms?
![Page 26: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/26.jpg)
Extinction of Species
• Primary causal mechanisms for extinction
• Reduction of population sizes
• Habitat changes
![Page 27: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/27.jpg)
![Page 28: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/28.jpg)
What pushes numbers of a species down to the point where it is pushed to extinction?
![Page 29: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/29.jpg)
Fossil Record and Mass Extinctions
• Many events, many hypotheses
• Pleistocene – megafauna of N. and S. Amer. 8,000 – 15,000 yr ago
• Once thought to be climate change from recession of glaciers
• More evidence that human colonization was a major contributor
![Page 30: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/30.jpg)
Fossil Record and Mass Extinctions
• Permian-Triassic 250 mya
• 96% of marine species lost
• Causal Agent?– Climate change but how– Glaciation– Global warming
–Massive volcanic activity– Continental drift
![Page 31: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/31.jpg)
Seabed in P-T before and after mass extinction
> 100 Species 4 - 5 Species
![Page 32: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/32.jpg)
Species Selection
• What leads to species surviving and radiating after extinctions?
• Appear to be key traits
• Remaining species in range also a factor
![Page 33: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/33.jpg)
• Expansion of mammals after K-T extinction (65 mya)
• Filled niches left behind by dinosaurs and reptiles pushed to extinction
![Page 34: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/34.jpg)
Placental Mammals
• Found globally in fossil record
• Few extant species in N. & S. America
• Australian marsupials
• Why?
• Adaptive radiation in absence of dominant reptiles
• Later natural and human intro of placentals
![Page 35: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/35.jpg)
Dispersal Advantage
![Page 36: Systematics Study of pattern and processes associated with biological diversity and diversification Taxonomy – study of classification (hierarchy, naming](https://reader030.vdocuments.site/reader030/viewer/2022032605/56649e745503460f94b74572/html5/thumbnails/36.jpg)
Replacement